One currently popular style of household refrigerator, called a side-by-side, comprises vertically disposed compartments, one compartment being maintained at a below freezing temperature for the storage of frozen food and the other compartment being maintained at an appropriate above freezing temperature for the storage of fresh foods.
Often the compartments are provided with individual liners and the vertical insulating divider wall separating the compartments is formed by the adjacent spaced apart wall portions of the two compartment liners. The forward edge of the divider wall is formed by a mullion or trim strip which extends from top to bottom of the refrigerator and bridges the space between the front edges of the two adjacent liners. The entire refrigerator cabinet including the central vertical dividing wall is insulated by a method termed "foam in place" which comprises injecting a suitable plastic in liquid form through the rear surface of the refrigerator which expands and flows in and around the liner structure to provide the necessary insulation.
To assure the penetration of the foam to all regions of the refrigerator cabinet where insulation is required, moderately high pressures must be developed during the foaming process. Accordingly, it is essential that all portions of the refrigerator be leak proof to prevent the escape of foam during the foaming process.
A particular problem has been encountered in suitably sealing the mullion strip which forms the front edge of the central vertical divider wall. Prior proposals such as the use of special adhesives, spacers and the like have proved to be generally unsatisfactory either because they failed to provide the required seal or because they were difficult to install or because of cost factors.